Gap connector in ignition generators



July 29, 1941. w. E. SCHWARZMANN 2,250,682

GAP CONNECTOR IN IGNITION G'ENERATORS Filed May 9, 1940 4 /5 /Z /7 m" M /M/ 4\\ f w l I #5: g ;L 1} I 12 I i J a 1 \i I x\ \Q 1 7 L1 (22 7 5 INVENTOR.

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ATTORNEY of high tension ignition currents to the distributor surface area between the electrodes increased .a gap connector with a comparatively large value 45 formed by a cup electrode fastened on the axis of Patente'd'July 29, 1941 I v UNITED s'rA'ras ,PATENT OFFICE oar coNNao'roa IN IGNITION oauaaa'roas Wolfgang E. Schwaramann, Longmeadow, Mala. I minor to American Bosch Corporation, Springfield, Macs a corporation of New York Application May 9, 1940-, Serial No. 334,162

Y 8 Claims. (01.171-209) The present invention relates to gap connectors gap connector comprises two electrodes of which with axially telescoped electrodes of which one is one is recessed closely and compactly within the stationary and the other is rotatable with an another to conductthe current impulses through an nular gap between them; said electrodes being air gap therebetween which has a large surface electrically connected between the high tension area and a comparatively small length or radial terminal of a stationary ignition coil and the disdepth. The two electrodes of the gap are thus .tributor rotor of or for multicylinder ignition telescoped" to form a gap of generally annular generators, such as magnetos and timers, for the form, having in some cases if desired an addipurpose of conducting the intermittent impulses tional end or disc gap, whereby not only is the for sequential distribution thereof to high tenconsiderably in comparison with gaps of the well sion sparkplugs of an associated internal com:- known iorm in Jump spark distributors but a parbustion engine. tially enclosed space is formed between the rela- Heretcfore a carbon brush was used to electively rotatable electrodes which confines the trically connect the ignition coiltothe distributor 1 heated gases therebetween and thus enhances rotor. but trouble developed, particularly in aviaand stabilizes the ionized condition of those gases tion magnetos and timers operating under severe which further reduce the drop in voltage through vibration. due to many causes such as the wear the gapconnector. In this way, not only is the and breakage of the brush, the depositionof ignition increased in eiiectiveness and reliability, carbon particles and smear from the brush, resulting in improved overall engine output and pitting and corrosion resulting from sparking dependability, but thegap connector outlastsmany and arcing, and the .breakage of the brush spring of the other parts of the magneto or timer due to due to crystallization. When the spring pressure the marked reduction'in pitting, corrosion and was increased in an endeavor to prevent arcing, erosion of the electrodes. These and other adthe brush wear increased, and thearcing in- 2 vantages, such as compactness, cheapness and creased when the spring pressure was decreased. ease of assembly and disassembly, will be appar- Brushes of metal and springs of different forms ent from the following descriptiontaken in conto obviate some of these troubles have performed nection with the accompanying drawing, illusunsatisfactorily. In service, these troubles ledtrating several embodiments of my invention as to the requirement for frequent repair and re- 3 applied, as examples, to magnetos having Jump placement which sometimes introduced dangers spark distributors incorporated therein and to in fli t w n used on airplanes; On the other magnetos or timers associated with independently hand, if a gap connector of ordinary form is used driven distributors. In the drawing, in the circuit between the ignition coil and the Fig. 1 shows in central elevational section a distributor rotor, the impedance of this gap plus magneto with the high tension terminal of its that of the air gap between the rotor and each stationary ignition coil in the form of a cup elecof the stationary electrodes of the distributor to trade into which extends a rod electrode fastened which the sparkplug cables are connected, may to the distributor rotor on the axis of rotation result in such high total spark energy loss that thereof to form a gap connector therewith; Fig. 2 under some conditions the effectiveness of the is an enlarged section on line 2-2 of Fig. i; Fig, 3 ignition sparks at the spark plugs is reduced and is a modified form of gap connector in which the likewise the p w Output nd dependability of outer electrode is in the form of a ring carried the engine. by the coil terminal; and Fig. 4 shows a sepa- In accordance with one part Of m inven ion, rate distributor in which the gap connection is of electrical capacitance or comparatively low the distributor rotor and a pin electrode provalue of impedance is provided in the circuit bejecting into the cup from a bracket electrically tween the stationary high tension ignition coil connected to a cable from the ignition coil of the and the rotary electrode of a jump spark disgenerating element of the ignition source.

tributor to conduct the current impulses for dis I5 R ferring to the embodiment of Figs. 1 and 2, tribution to the sparkplug cables. In a cordthe numeral I generally designates a magneto ance with another part of my invention, whether having a generating rotor 2 and a stator struca jump spark or a brush type distributor is used, ture I, of any suitable kind, with a stationary igand whether .the distributor is incorporated in nition coil 4 having primary and secondary the magneto or timer or separated therefrom, the windings of well k own kind. The live end of the secondary or high tension winding is connected to a terminal 5 of a suitable nickel alloy fastened rigidly in position on the 'coil by a rivet or soldering at 6 and having a cylindrical cavity or recess at l forming a cup-shaped member. The generating rotor 2 carries a pinion 8 meshed with a distributor gear 9 of suitable ratio mounted for rotation in the ball bearing I0. To the gear is fastened by screws II the distributor rotor i2 of insulating material. Molded in this rotor is a distributor arm or electrode l3 riveted or otherwise fastened along its axis'of rotation to a generally cylindrical pin or rod ll of a suitable nickel alloy which projects centrally into the The cylindrical collar ll serves to molding and the annular projection it of the molding electrically shrouds the gap connector against flashover to the metal parts of the magneto. The outwardly projecting part i? of the electrode l3 registers seuentially with the stationary distributor electrodes 18 of the magneto, which terminals are mounted in the distributor plate IQ of insulating material and are fastened electrically by piercing screws 23 to the sparkplug cables 2!. The stationary member 22 of insulating material forms an apron under the distributor rotor to prevent flashover from the projecting portion H to metal parts of the magneto.

The modified gap connector of Fig. 3 has the axially rotatable metal pin or rod 23 fixed in a rod 25 extending from the distributor rotor electrode (not shown) which pin or rod projects into the metal ring 25. This ring is adjustably suspended from the terminal 2B of the stationary ignition coil i by a metal arm 21 which may be bent or adjusted to give an annular gap between the electrodes 23 and 25 of substantially uniform depth. As before, the shroud 28 is of insulating material and integral with the rotor of the distributor which may be of the brush or jump spark type.

In the embodiment of Fig. 4, the rotor 29 of the distributor, which is dlsassociated from the generating element of the magneto, timer or other ignition source, is driven by the engine through gearing of the proper ratio (not shown). In this case it is the electrode 30, fastened to the arm (H on the axis of the distributor rotor that is,cupshaped, while the pin or rod electrode 32 projects thereinto to form annular and disc gaps therewith. The gap connector thus formed is protected by the shroud 33 and the electrode 32 is suspended by a bendable arm 34 from a bracket 35 which in effect forms the, terminal of the high tension ignition coil by being electrically connected by the piercing screw 36 to the cable 21 that leads from the ignition coil. This arm may be bent or adjusted to give the desired gaps. In this embodiment, a jump spark distributor is shown but it may be replaced by one of the brush type in ways that will be obvious.

It will be observed that the annular air gaps of the gap connector of all embodiments herein described, particularly when supplemented by the additional disc gaps of Figs. 1 and 4, have a cross sectional area so much greater, on account of the telescoped electrodes, than that between the electrodes of a jump spark distributor, and can have a length or radial depth so much less, on account of the small diameter of the gap and the mounting of the rotatable electrode thereof at the axis of the distributor rotor instead at a place removed therefrom, that the current carrying capacity of these gap connectors between the sparking voltage in this ignition coil and the distributor is considerably greater, and the impedance thereof considerably less, than that of any of the gaps or the jump spark distributor. In fact, the annular gap can have almost no depth by initially providing little or substantially no tolerance between the electrodes thereof. The result is that the loss in type of gap connector between the ignition coil and the distributor is so small that the characteristics of the ignition spark at the sparkplugs in the engine cylinder are not affected to any noticeable extent. At the same timethe troubles above noted in a brush connector between the coil and distributor are obviated. Also, the surfaces in registration between the members of these forms of gap connectors are so extended on account of being telescoped, and the annular gaps can be maintained so uniformly in depth on account of their small diameter, that the sparking between the gap electrodes is divided at each period of ignition or readily shifts to different places at dinerent periods of ignition, which thereby reduces the pitting and erosion over the electrodes to such an extent that the gap connector functions satisfactorily over longer periods of operation than ,do gap connectors of prior constructions. Furthermore, the sparking zones of these gap connectors are so restricted or partially confined from ventilating air currents, particularly on account of the insulating shroud around them, that the air or gases between the telescoped electrodes quickly becomes stabilized in an ionized condition which further decreases the impedance of the gap connector. The ionized and corrosive gases in this gap connector being partially confined in the annular gap are not so readily difiused with the surrounding air and, therefore, do not become harmful to the other parts of the ignition apparatus. If desired, the ventilating passages 38 may be provided in any of the gap connectors in the event that either electrode thereof gets too hot in operation.

It is obvious that other modifications of my gap connectors and their incorporation in magnetos. timers or other ignition generators may be provided within the broad terms of the appended claims and such modifications also are therefore intended to be covered thereby.

Having thus described my invention, claim is:

1. In a multicylinder ignition system for high tension sparkplugs of an internal combustion engine, a stationary ignition coil having a high tension terminal, a source of intermittent current supply for said coil, a jump spark distributor having a rotatable electrode and a plurality of stationary electrodes for connection to respective sparkplugs, said rotatable and stationary electrodes registering sequentially with an air gap therebetween, and a gap connector electrically connected between said coil terminal and said rotatable electrode of said distributor and having axially telescoped electrodes of which one is stationary and the other isrotatable with an annular gap between them, the impedance of said gap connector being less than the impedance of any of said distributor gaps.

2. In a multicylinder ignition system for high tension sparkplugs of an internal combustion engine, a stationary ignition coil having a high tension terminal, a source of intermittent current supply for said coil, a distributor having a distributor rotor and a. plurality of stationary sparkplug terminals sequentially registerable therewhat I with, and a gap connector electrically connected between said coil terminal and said distributor rotor and having axially telescoped electrodes of which one is stationary and the other is rotatable with an annular gap between them.

3. In a multicylinder ignition system for high tension sparkplugs of an internal combustion en gine, a stationary ignition coil having a high tension terminal,= a source of intermittent current supply for said coil, a distributor having a distributor rotor and a plurality of stationary sparkplug terminals sequentially registerable therewith, and a gap connector electrically connected between said coil terminal and said distributor rotor and having axially telescoped electrodes of which one electrode is stationary and the other is rotatable with an annular gap between them and of which one electrode is cupshaped with a disc gap between its bottom sur face and the other electrode.

4. In a multicylinder ignition system for high tension sparkplugs of an internal combustion engine, a stationary ignition coil having a hightension terminal, a source of intermittent current supply for said coil, a distributor having a distributor rotor and a plurality of stationary sparkplug terminals sequentially registerable therewith, and a gap connector electrically connected between said coil terminal and said distributor rotor and having axially telescoped electrodes of which one electrode is stationary and the other is carried by the distributor rotor on the axis of rotation thereofto i'orm an annular gap with the stationary electrode.

5. In a multicylinder ignition system for high tension sparkplugs oi an'internal combustion engine, a stationary ignition coil having a high tension terminal, a source of intermittent current supply for said coil, a distributor having a distributor rotor and a plurality of stationary sparkplug terminals sequentially registerable therewith, and a gap connector electrically connected between said coil terminal and said distributor rotor and having axially telescoped electrodes of which one is stationary and the other is rotatable with an annular gap between them, one of said ried by the distributor rotor on the axis of rotation thereof to form an annular gap with the said coil terminaL' 1 7. In a multicyli-nder ignition system for high tension sparkpiugsof an internal combustion en gine, a stationary. ignition 0011 having a high tension terminal, a source .of intermittent current supply for said coil, a distributor having a distributor rotor and a plurality of stationary sparkplug terminals sequentially registerable therewith, and a rotatable gap connector with axially telescoped electrodes of which one electrode is supported from said coil terminal by a bendableconducting support extending therefrom and of which the other electrode is carried by said distributor rotor in electrical connection' therewith to form an annular gap with theflrst named electrode.

8. In a multicylinder ignition system for high tension sparkplugs of an internal combustion engine, a stationary ignition coil having a high tension terminal, a source of intermittent currentv supply for saidlcoil, a distributor having a distributor rotor and a plurality of stationary sparkplug terminals sequentially registerable therewith, and a gap connector electrically connected between said coil terminal and said distributor rotor and having axially'telescoped electrodes of which one electrode is stationary and the other is rotatable with an annular gap between them, the outer one of said telescoped electrodes having a ventilating passage through it.

WOLFGANG a. SCHWAR'ZMANN. 

